A. Technical Field
The present invention relates to a racing tire tread rubber composition.
B. Background Art
As to a racing tire that might be run on a road wet with rain and so on, it is important to enhance the wet grippability of the tire. Generally proposed methods for enhancing the wet grippability comprise, for example, increasing the following factors: (1) the hysteresis loss; (2) the adhesive friction; and (3) the turning-up friction.
Thus, in recent years, a method for enhancing the wet grippability has been studied in which the adhesive friction is increased by adding a large amount of fillers such as silica. However, a tire containing a large amount of silica has many problems in the production. The most serious problem is a phenomenon which is called excessive adhesion. This phenomenon causes a problem in that when a rubber composition is kneaded or extruded during a tire manufacturing process, it strongly adheres to a kneading or extruding apparatus, so that the adhered rubber composition is very difficult to remove, or that the above-mentioned apparatus needs to be washed carefully after processing every batch.
A. Object of the Invention
An object of the present invention is to provide a racing tire tread rubber composition which is used for producing a racing tire having excellent wet grippability and does not cause any excessive adhesion in tire production process steps such as the kneading and extruding steps.
B. Disclosure of the Invention
The present inventors studied diligently about the types or the amount of the combination of additives, which are combined into a racing tire tread rubber composition containing silica, in order to solve the above-mentioned problems. As a result, the inventors attained the present invention.
Thus, a racing tire tread rubber composition, according to the present invention, is a composition comprising: 100 parts by weight of a diene-based rubber; a filler, the entirety of which is in the range of 100 to 250 parts by weight containing 20 parts by weight or more of silica; and 5 to 50 parts by weight of a factice.
These and other objects and the advantages of the present invention will be more fully apparent from the following detailed disclosure.